The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 24, 2014
Filed:
Nov. 13, 2012
Maruzen Petrochemical Co., Ltd., Tokyo, JP;
Tomo Oikawa, Ichihara, JP;
Maruzen Petrochemical Co., Ltd., Tokyo, JP;
Abstract
A method for producing a resist copolymer having a weight-average molecular weight of not less than 3000 and not more than 6000, in which copolymer the contents of an oligomer having a molecular weight of not more than 1000 and a byproduct derived from a polymerization initiator are small, is provided. The method for producing a resist copolymer comprises the step of continuously supplying a solution containing a monomer and a solution containing a polymerization initiator to a heated solvent to carry out a radical polymerization, wherein the variation range of the concentration of the polymerization initiator in polymerization solution is within ±25% of the median value between the maximum concentration and the minimum concentration during specific time; and the variation range of the concentration of unreacted monomer in the polymerization solution is within ±35% of the median value between the maximum concentration and the minimum concentration during specific time.